The three-month-old moggies were tied inside and stained in their own urine.

The dog walker took the stressed animals to a vet and the Scottish Society for the Prevention of Cruelty to Animals launched a media appeal. Television coverage led to the original owner coming forward and explaining how she had handed the kittens over to 63-year-old Mountain after her own cat had produced a litter.

And at Jedburgh Sheriff Court Mountain admitted abandoning the animals and causing them unnecessary suffering on August 26.

The court heard on Friday she had thrown the cats – which were later named Midnight and Shadow – over a bridge between Melgund Place and Linden Crescent in Hawick.

The pensioner, formerly of Park Street in Hawick, but now living in Argyll, was banned from keeping animals for five years and fined £150.

Her actions have been slammed by the Scottish SPCA. Chief Superintendent Mike Flynn blasted: “Tying two defenceless kittens in a bag and leaving them for dead is callous beyond belief.

“If they hadn’t been found by a lady walking her dog they wouldn’t have survived as they had no food or water and a limited air supply.

“This was a shocking case of deliberate cruelty. As well as a ban on keeping animals, Mountain also now has a conviction for abandoning her two cats and a criminal record.

“Thankfully, Midnight and Shadow recovered from their ordeal and have both gone on to find the loving homes they deserve.”

After the original owner came forward in response to the media appeal, Mountain was quizzed by an animal cruelty inspector and acknowledged ownership but claimed she had passed them on to someone else.

However, Sheriff Donald Corke was told that once the inspector challenged her, she confessed that she had got rid of the pets.

Prosecutor Keith O’Mahony told the court: “She said she had put them in a black bin bag and threw them over the side of a bridge at about 3am. She said she was going on holiday.”

They were found by the dog walker four hours later. Mountain, a first offender, agreed to hand over ownership to the SSPCA. And she told them: “I’m sorry. I just panicked.”

Defence solicitor Greig McDonell said his client had been drinking heavily at the time after splitting from her partner and suffering depression.

He went on: “She has little recollection of the incident. Everything was getting on top of her, and she has expressed her sorrow to the SSPCA and also to the court.

“She currently has no animals, and accepts that a disqualification from keeping them may be merited, and doesn’t seek to oppose that.”

Sheriff Corke told her: “It is difficult to sentence in a case like this, as the sentence has to be proportionate to other kinds of misery we see in the sheriff court.

“You have reached the age of 63, without committing any other offences. I hope this fine will make you pause and consider before acting towards any animal in this way.” `